accessr
One R Markdown source, four accessible formats — and a fortnight spent patching around someone else's bug.
A side-by-side editorial comparison of dockViewR and SLmetrics — release velocity, themes, recent moves, and the top alternatives to consider.
Draggable dock panels for Shiny, learning that layout state belongs on the client
dockViewR wraps the dockview JavaScript library so Shiny apps can offer draggable, splittable, tabbed panel layouts — the IDE arrangement, driven from R. Three releases since May 2025 have taken it from a working widget to one with a proper server-side control surface: panels can be added, removed, selected and moved from the server, and the dock exposes a reactive proxy.
A young ML metrics package rewrote its own backend twice in six months chasing speed.
SLmetrics provides supervised learning evaluation metrics for R — confusion matrices, classification and regression measures, ROC and precision-recall curves — with the computation pushed into C++. After a series of pre-releases it now runs on an Armadillo backend, supports OpenMP parallelism and LAPACK/BLAS, and reports 5-20x speedups over its earlier implementations. The API has been reshaped for extensibility, with an estimator argument replacing the fixed aggregation options.
dockViewR wraps the dockview JavaScript library so Shiny apps can offer draggable, splittable, tabbed panel layouts — the IDE arrangement, driven from R. Three releases since May 2025 have taken it from a working widget to one with a proper server-side control surface: panels can be added, removed, selected and moved from the server, and the dock exposes a reactive proxy.
The design has been converging on the standard htmlwidgets pattern, and 0.3.0 is where it commits. Earlier releases routed panel-id checks through Shiny inputs, which meant the state was stale until the next reactive flush and forced awkward workarounds when manipulating the dock inside observeEvent(). Moving those checks to the browser and adding dock_view_proxy() drops that class of bug entirely, at the cost of a breaking API change and a dev-mode option for surfacing the warnings.
Having taken one breaking change to reach the proxy idiom, the natural follow-on is filling out the proxy surface so every panel operation is reachable through it.
SLmetrics provides supervised learning evaluation metrics for R — confusion matrices, classification and regression measures, ROC and precision-recall curves — with the computation pushed into C++. After a series of pre-releases it now runs on an Armadillo backend, supports OpenMP parallelism and LAPACK/BLAS, and reports 5-20x speedups over its earlier implementations. The API has been reshaped for extensibility, with an estimator argument replacing the fixed aggregation options.
Every release in this timeline is about making the same metrics compute faster or compose better. The backend moved from Rcpp to plain C++, gained OpenMP, then was ported wholesale from Eigen to Armadillo with heavy templating. In parallel the author has been widening the API's joints: generic S3 signatures, an extensible estimator argument, and function signatures loose enough that wrapping packages can rename arguments. Bundled datasets and embedded formulas in the docs point at teaching and benchmarking use. The package still labels itself pre-release, which is consistent with how freely it has broken argument names along the way.
A stable non-pre-release version is the natural next step now that the backend has settled on Armadillo, though the repeated willingness to rename arguments suggests more API churn may come first.
Other Infra & APIs products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either dockViewR or SLmetrics.
One R Markdown source, four accessible formats — and a fortnight spent patching around someone else's bug.
The R package that installs Java for you stopped needing an update every time Java ships.
The AusTraits engine, generalised for anyone's trait database, now links measurements to real specimens.
The toolchain that gets R packages into the browser is optimising for payload size, not features.
Fail2Ban finally ships 1.1.1 after 14 months in beta, with a botched deb package on the way out the door
A logging header for Rcpp packages that sat untouched for nine years, then changed how it switches on
See all dockViewR alternatives → · See all SLmetrics alternatives →
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
Both compete on the same themes — r-package — within Infra & APIs. dockViewR and SLmetrics are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. dockViewR and SLmetrics are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). For your specific use case, the alternatives sections above list other Infra & APIs products to evaluate alongside.
Top dockViewR alternatives in Infra & APIs are ranked by recent ship velocity. Browse the "dockViewR alternatives" section above for the current picks, or visit /alternatives/dockviewr for the full list with editorial commentary on each.
Top SLmetrics alternatives in Infra & APIs are ranked by recent ship velocity. Browse the "SLmetrics alternatives" section above for the current picks, or visit /alternatives/slmetrics for the full list with editorial commentary on each.